THE SPACE SHUTTLE

The Space Shuttle was the world's first partially reusable orbital spacecraft system, operated by NASA from 1981 to 2011. Officially known as the Space Transportation System (STS), it was designed to carry crews and heavy payloads, such as the Hubble Space Telescope and modules for the International Space Station (ISS), into low Earth orbit. 

 

A total of six orbiters were built, five of which were space-worthy: 

 

Enterprise (OV-101): The prototype used for atmospheric landing tests; it never flew in space.

Columbia (OV-102): The first to fly in space (1981). It was lost during reentry in 2003.

Challenger (OV-099): The second operational orbiter. It was lost during launch in 1986.

Discovery (OV-103): The fleet's workhorse, completing a record 39 missions.

Atlantis (OV-104): Flew the final mission (STS-135) in July 2011.

Endeavour (OV-105): Built to replace Challenger, it flew 25 missions. 

 

The system consisted of three major parts at launch: 

The Orbiter: The reusable "space plane" that housed the crew and cargo. It landed on a runway like a glider.

External Tank (ET): The large orange tank containing liquid hydrogen and oxygen to fuel the orbiter's main engines. It was the only non-reusable part.

Solid Rocket Boosters (SRBs): Two white rockets that provided 80% of the initial thrust. They were jettisoned after two minutes, parachuted into the ocean, and were recovered for reuse